Embodiments relate to a light emitting device, a light emitting device package, and a lighting system including the light emitting device and the light emitting device package.
In light emitting devices, P—N junction diodes having the properties of converting electrical energy into light energy may be formed by combining group III and V elements on the periodic table. Light emitting devices may implement various colors by controlling the composition ratio of compound semiconductors.
In light emitting devices, when a forward voltage is applied, an electron of an n-layer is combined with a hole of a p-layer to emit energy corresponding to an energy gap between the conduction band and the valance band. The energy is generally emitted in the form of heat or light. In light emitting devices, the energy is emitted in the form of light.
Nitride semiconductors, for example, are attracting much attention for the fields of optical devices and high-power electronic devices because of their high thermal stability and wide band gap energy. In particular, blue light emitting devices, green light emitting devices, and UV light emitting devices that use nitride semiconductors have been commercialized and are widely used.
Although a light extraction structure is used to improve a light extraction efficiency of a light emitting device in the related art, the light extraction efficiency does not reach an ideal value.